Finding the Third Proportional to 85,597.50 and 128,659.50

Step by Step Solution

1. Step 1: Write the proportion equation
   85,597.50 : 128,659.50 = 128,659.50 : x
2. Step 2: Convert to fraction form
   85,597.50/128,659.50 = 128,659.50/x
3. Step 3: Cross multiply
   85,597.50x = 128,659.50 × 128,659.50
4. Step 4: Simplify right side
   85,597.50x = 16,553,266,940.25
5. Step 5: Solve for x
   x = 16,553,266,940.25/85,597.50
6. Step 6: Final answer
   x = 193,384.93